Patentable/Patents/US-6393448
US-6393448

Optical random-number generator based on single-photon statistics at the optical beam splitter

PublishedMay 21, 2002
Assigneenot available in USPTO data we have
Inventorsnot available in USPTO data we have
Technical Abstract

A random-check generator for generating a random number, which is preferably represented in binary form, having a particle source, a random-check generating element which acts on particles emitted by the particle source, and a detection system which allocates a numerical value, preferably in binary form, to the detection of a particle emerging from the random-check generating element. The random-check generator is not susceptible to external interference and delivers high-quality random numbers. To that end, the particle source can emit at least two particles substantially simultaneously, and one particle can activate the detection system in order to detect a further particle influenced by the random-check generating element and allocate a numerical value thereto.

Patent Claims
16 claims

Legal claims defining the scope of protection, as filed with the USPTO.

1

1. A random-number generator for generating a random number, the random-number generator comprising: a particle source capable of emitting at least a first and a second particle more or less simultaneously; a random-number-generating element acting on particles emitted by the particle source; and a detection apparatus for associating a numerical value with a detection of a particle leaving the random-number-generating element; wherein the first particle is capable of activating the detection apparatus so as to detect the second particle and associate a numerical value with the second particle, the second particle being influenced by the random-number-generating element.

2

2. The random-number generator as recited in claim 1 wherein the random number is represented in binary form.

3

3. The random-number generator as recited in claim 1 wherein the numerical value is represented in binary form.

4

4. The random-number generator as recited in claim 1 wherein the particle source includes a photon-pair source for simultaneously generating two photons with correlated polarization, energy and spatial emission distribution, the two photons being the first and second particles.

5

5. The random-number generator as recited in claim 4 wherein the detection apparatus employs a single-photon receiver for detecting the activating trigger photon of the photon pair.

6

6. The random-number generator as recited in claim 1 wherein the random-number-generating element includes a beam splitter having outputs associated with two receivers for detecting single photons.

7

7. The random-number generator as recited in claim 6 wherein the detection apparatus employs a single-photon receiver for detecting the activating trigger photon of the photon pair.

8

8. The random-number generator as recited in claim 1 wherein the detection apparatus includes combined coincidence/anticoincidence electronics.

9

9. The random-number generator as recited in claim 1 wherein the random-number-generating element includes a polarizing beam splitter.

10

10. The random-number generator as recited in claim 9 wherein the random-number-generating element includes an upstream /2 retardation plate for adjusting the overall splitting ratio.

11

11. The random-number generator as recited in claim 19 wherein the polarizing beam splitter and the /2 retardation plate are jointly held in positions aligned with respect to each other.

12

12. The random-number generator as recited in claim 1 wherein the random-number-generating element includes a nonpolarizing beam splitter.

13

13. The random-number generator as recited in claim 12 wherein the nonpolarizing beam splitter includes a metallized plate and/or a dielectric layer.

14

14. The random-number generator according to claim 12 further comprising detection electronics and adjustable masks and/or tunable spectral filters disposed in outputs of the beam splitter so as to balance an optical path and the detection electronics.

15

15. The random-number generator as recited in claim 1 wherein an overall splitting ratio between individual outputs of the random-number-generating element is set by optical and/or electronic apparatuses to an approximately equal splitting ratio.

16

16. The random-number generator as recited in claim 1 wherein the splitting ratio is 50:50 for two-photon emission.

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Patent Metadata

Filing Date

June 14, 1999

Publication Date

May 21, 2002

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Cite as: Patentable. “Optical random-number generator based on single-photon statistics at the optical beam splitter” (US-6393448). https://patentable.app/patents/US-6393448

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